1. Technical Field
The disclosure relates to a wireless communication system and routing method for a packet switched service, femto AP using the routing method.
2. Background
According to research data of various studies, a proportion that users use mobile phones at home is rapidly growing, and considering the other indoor commercial usage environments such as offices, nearly 60-70% mobile communications are occurred indoors according to NTT DoCoMo's statistics. In the future, in case that a bandwidth requirement of digital contents is greatly increased, and a difficulty for constructing an outdoor base station is increased due to environmental protection protests, indoor communication capacities can be seriously insufficient. Therefore, a Femto Access Point (AP) having low power and high frequency bandwidth could be a good solution. The Femto AP allows a user to connect to a mobile core network for accessing telecom services under an indoor environment.
The Femto AP is a small and low power cellular base station, which is mainly used in indoor places such as at house and at offices, etc., so that it is also referred to as a home node B (HNB). The Femto AP serves as a compensation of indoor coverage of a cellular network, and provides the user with voice and data services. A profile of the Femto AP is generally similar to a wireless fidelity (Wi-Fi) AP, which can be independently used, and can also be integrated in a home gateway to serve as a part of a home network.
FIG. 1 is a schematic diagram illustrating a Femto AP network structure. A user indoor can use a user equipment (UE) to connect the Femto AP through a standard mobile communication access protocol. Such standard mobile communication access protocol is, for example, a wideband code division multiple access (WCDMA) protocol or a high speed download packet access (HSDPA) protocol, etc., which is determined according to an applied communication system. Moreover, other Femto APs (for example, a Femto AP 122) can be configured at other areas.
A UE 110 is connected to the Femto AP 120, and the Femto AP 120 transmits messages or data packets between the UE 110 and a Femto gateway (GW) 140 through a broadband IP network 130 according to an Internet protocol (IP). The Femto GW 140 transmits the IP messages or the data packets between the Femto AP 120 and a mobile core network 150.
A communication path between a user of a wireless communication device 111 of the Femto AP 120 and a user of a wireless communication device 113 is established sequentially through the Femto AP 120, the broadband IP network 130, the Femto GW 140, a mobile switching center (MSC) of the mobile core network 150, and outdoor base station.
In a present Femtocell network structure, when the UE is about to use a packet switched (PS) service, for example browsing a website, a session has to be established between the UE and the mobile core network 150. In an example, under universal mobile telecommunication system (UMTS) architecture, data of such session is recorded in a packet data protocol (PDP) context, which includes an IP address assigned to the UE, a session quality of service (QoS), and a routing information, etc., and are respectively stored in the UE and nodes of the mobile core network 150, for example, a serving GPRS support node (SGSN) and a gateway GPRS support node (GGSN) (for example, a SGSN 152 and a GGSN 154 shown in FIG. 1), where the GPRS is the so-called general packet radio service.
The SGSN 152 is to transfer wireless data of the user to the GPRS network. Moreover, data transmitted to the GGSN 154 from an external network is transmitted to the SGSN 152, and is then transferred to a wireless network interface for the user. The GGSN 154 is used for transferring packets of an internal network of a system service provider to the external network, and transferring packets of the external network to the internal network of the system service provider. For example, the GGSN 154 switches packet data with an Internet service provider (ISP) (for example, a Google server 162 or a Yahoo server 164) in the Internet 160. Since connection approaches of the two terminals are probably different, the GGSN node 154 has to perform operations of data cutting, packet conversion, and so on.
The UE 110 and the Femto AP 120 are used to describe a flow of obtaining the service provided by the ISP with reference of FIG. 2.
When the mobile core network 150 allows the UE 110 to establish the PDP context, the session QoS between the UE 110 and the Femto AP 120 and between the Femto AP 120 to the mobile core network 150 are set by a radio access bearer setup procedure. After the radio access bearer setup procedure is completed, an activate PDP context accept message is transmitted back to the UE 110, which means that the procedure of establishing the PDP context is finished. Now, the UE 110 obtains an IP address assigned by the mobile core network 150. After the UE 110 obtains the IP address, the UE 110 can access the PS service (for example, the service provided by the Google server 162) according to the IP address. During a data transmission, a transmission path thereof is shown in FIG. 1, which is routed through the UE 110, the Femto AP 120, the broadband IP network 130, the Femto GW 140 in the mobile core network 150, the SGSN 152, the GGSN 154, and the Google server 162. According to the system of FIG. 1, if the UE 110 is going to access data of the Google server 162, a path thereof has to be from (a), (b), (c), (d), (i), (j) to (f).
According to the above descriptions, it is known that transmission of the packets of all of the Internet services 160 has to be routed through the mobile core network 150, and when a data amount is greatly increased, a burden of the mobile core network 150 is greatly increased, and extra equipments have to be added to carry on these services.